The invention relates to locking devices, and more particularly to locking devices for use with network interface devices (NIDs).
Network interface devices (NIDs) or Network Interface Units (NIUs) house telephone line junctions and terminals. As used herein, the terms NID and NIU are interchangeable. The NID may provide either residential or commercial line access to one or more subscribers. The NID is typically placed between the subscriber""s wiring and the service provider""s subscriber loop.
Typically, the NID is sectioned for separate subscriber and service provider access. Each subscriber line terminal is typically covered by a hinged plate. Subscribers or service providers can usually access their individual lines in the compartment by lifting the plate, thereby exposing the subscriber line terminal. In many configurations, the compartment for a loop junction is limited to service provider access.
In most NID configurations, the individual subscriber line access cover plate is designed to be readily accessed. The line access covers are typically one inch wide and two inches in length, although there are known variations to these designs. Many configurations of these covers comprise a slot through which an apertured flange fixed to the NID housing may pass. A subscriber may place a small padlock through the aperture in the flange to prevent the cover from being lifted.
Unfortunately, present NID designs which enable easy access by subscribers and service providers, also permit access by unauthorized persons. The relatively small sized padlocks used for this application are known to have poor tamper-resistant characteristics. Additionally, due to the size of the cover, small padlocks must be used which are often difficult to use given dexterity limitations of individuals and/or the environmental conditions (i.e. poor lighting) at the NID. Even expensive small locks having improved tamper-resistant features also present similar problems. Additional problems result when a subscriber breaks a key in the lock or is unable to use the key provided with the lock due to the poor quality of the lock and key assembly. Further, larger locks, such as those having a combination or traditionally-sized keys, are typically not an option due to the size and physical limitations of the NID enclosure.
Consequently, line access in NIDs remains relatively poorly secured thereby exposing the subscriber to potential costs related to repair, theft and damage, particularly for NIDs accommodating numerous subscriber junctions.
Accordingly, there exists a need to economically and simply secure line access in NID configurations, and the like. There exists a need to provide a tamper-resistant solution that may be used in a relatively small area. There further exists a need for a device which is easily secured and removed by an authorized user of an existing NID cover configuration without affecting the operation of neighboring subscriber covers and/or accesses. Additionally, there exists a need to provide a device that locks a subscriber""s line access cover uniquely from other accesses on the same NID, thereby preventing one subscriber from accessing another""s line on the same NID.
Embodiments of the invention provide a locking device that may be used to prevent a subscriber from accessing another subscriber""s line on the same NID.
The locking device includes a slotted cylinder having a first end, a second end and a first slot. The first slot has a distal end and a proximate end. The slot""s proximate end coincides with the cylinder""s first end and extends from the first cylinder end longitudinally and partially toward the second cylinder end. The cylinder has a second slot extending from, and opened to, the first slot distal end at an angle to the first slot. The cylinder has a resistance component contained in the cylinder at its second end. A key, mateable with the slotted cylinder, has a shaft with a key head at the first end of the shaft. A flange extends from and at an angle to a second end of the shaft. The key head has a cavity therein. The device also includes a key tool which is mateable with the key head cavity. The key may be inserted into the slotted cylinder and turned to lock it therein. The key tool is used to release the key from the slotted cylinder.
A cylindrical sleeve may be utilized for additional security. The sleeve has a first end, second end, first inner diameter, second inner diameter, and a third inner diameter. The first inner diameter is larger than the outer diameter of the slotted cylinder so that the slotted cylinder may fit in the sleeve. The first inner diameter extends from the first sleeve and to a length corresponding at least to the length of the slotted portion and the slotted cylinder. The sleeve""s second diameter is larger than the key head so that the key head may fit at least partially within the sleeve. The second inner diameter extends from the second sleeve end to a length of at least about the key head length. The third inner diameter is positioned between the first inner diameter and the second inner diameter. The third inner diameter is larger than the key shaft diameter and smaller than the key head so that the sleeve cannot pass over the key head. A slot extending the length of the third inner diameter section and partially into the cylinder wall accommodates the key flange when the key is placed in the sleeve.
By use of different key head cavity shapes each subscriber may only access their own line in a NID.